Search Results

This paper conducts numerical simulation and wind tunnel testing to demonstrate the passive flow control jet boat tail (JBT) drag reduction technique for a heavy duty truck rear view mirror. The JBT passive flow control technique is to introduce a flow jet by opening an inlet in the front of a bluff body, accelerate the jet via a converging duct and eject the jet at an angle toward the center of the base surface. The high speed jet flow entrains the free stream flow to energize the base flow, increase the base pressure, reduces the wake size, and thus reduce the drag. A baseline heavy duty truck rear view mirror is used as reference. The mirror is then redesigned to include the JBT feature without violating any of the variable mirror position geometric constraints and internal control system volume requirement. The wind tunnel testing was conducted at various flow speed and yaw angles.

The heavy-duty diesel industry continues to expand the use of sophisticated electronic controls to reduce greenhouse gas emissions and improve fuel economy in the transportation sector. This inevitably leads to a need for increased knowhow in all aspects of embedded software development, e.g. in writing model-based specifications, rapid controls prototyping, automatic code generation, and hardware-in-the-loop (HiL) testing. In addition, the software development organization has to recognize the need to establish maturity in its verification and validation test framework, which includes, among other things, a proper definition of testing process and workflow, greater organizational focus, and a robust tool architecture for software testing. Navistar has already undertaken a model-based approach to software development and continues to improve their processes, technology, and tooling in this area.

Powertrain Systems development is entering a period of unprecedented challenge driven by the convergence of many factors: increasing government regulations for both tailpipe emissions and fuel economy, increased competition, reduced workforce, and tighter program budgets. This has resulted in timing compression and resource reduction that stress a typical Design-Build-Test development practice. The application of telematics and information technology to engineering development can provide the efficiency gains required for engineers to deliver a robust powertrain system in a timely manner. By automating the evaluation of a system's robustness, engineers can focus their time on problem areas during their normal development process and launch with quality. This paper will detail how this methodology was jointly applied by Control-Tec and Navistar to identify and improve system performance before production.